Well, tonight, there may be a secret cash cow parked in your driveway. Because that old car may actually be worth thousands of dollars more than you think. When it comes to receiving your own car, some quick, easy, do it yourself tips could help you increase the price, and there's a lot more to it than just hanging up a gas station air freshener in there. Abc's sharyn alfonsi brings us the best strategy for selling your old wheels. Reporter: Meet the gross family. Brian, his wife lauren, dog layla and that's their baby, who often gets into the car through the trunk. Doesn't take long to figure out why they need to sell their car. It's a disaster. Reporter: So, if your wife wanted to get in here she would have to sit like this, right? She would have to be, like, in the fetal position. The blue book value for the car is $9,000, but a local car dealer offered him four. He thinks it's worth more. So, brian is trying to sell it himself, putting up signs, listing it online at auto trader. Two mant months later, zero calls. The car is in fair shape. And it's supposed to be a seller's market. So, we called autotrader.Com and asked them to troubleshoot the gross' problem. They sent out brian moody, a sells expert who, with just a few simple changes, was able to help get the gross family an extra $3,000 for their car. Moody explained there are basic things anyone can do to get a top price for their used car. Key number o, clean it up. The coins, the traces of dog fur need to go. And lose the junk in the trunk. Someone wants to picture their stuff there, not necessarily your old stuff. Reporter: To that end, rethink your key chain. Yeah, I would ditch that. Reporter: Life is about reaching your designation but enjoying the trip. That sounds good. I picture this being a girl's car. Reporter: And finally, take a whiff. Have a woman, yes, a woman, smell your car. It turns out we have a better sense of smell. It's a little funky, but it's not awful. So, we get to work. Hot rims. Whoa. The car now sparkling, we focus on making the online ad pop. Right away, brian notices problems with the five pictures posted. The steering wheel needs to be straightened out. The sunroof closed. And all these other cars are distracting. It needs to look like a new car ad. So, we take new pictures outside, near a park, on a cloudy day so the light is even. But there's one more big hurdle. If you want a sharp looking car that handling great -- Reporter: The ad. You're really excited about selling this car. Brian says lose the exclamation points, the all caps and instead offer details about the car. And brian says that misspelling can cost you money. Why does that matter? Fwl they want to think you're taking as much care of your ad as you do the car. Reporter: And then, the price. Everybody thinks I's ill I'll price it high. While the blue book value is a good national average, but the indicator is what similar cars are selling for in your area. So, price it right. While we wait for buyers to bite, we bring in nicole markson, an automotive insider to teach brian how to show the car. She says individual sellers actually have a huge advantage over car salesmen. You have to remember, people are afraid to go to a car dealership. You want to make them feel warm and comfortable with you. If somebody doesn't like you, they're not going to buy from you. Reporter: If a couple is looking, remember, 85% of big purchases are ultimately made by the woman. And, she says, most importantly, have them drive the car before you ever talk about price. What you want to do is have them driving, really loving it and then having that discussion after. Reporter: But is all this really enough? The gross family is desperate for a bigger car. Days later, the new ad is being viewed twice as many times. And finally, an offer online. 7,000. 3,000 higher than the first offer. We're very hopeful we're going to sell the car really soon. Reporter: I'm sharyn alfonsi

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